Until relatively recently, car seat designs were relatively simple and flat. These simple designs reflected the level of attention paid by designers to the interior of the car. Seats were relatively simple to design and required only a few prototypes for new design approval before going into production.
However, in the mid-1980's, there was great interest in the design of automotive interiors including seats. Such new seats must be designed ergonomically to provide comfort and styled to provide visual appeal and a distinct appearance. Consequently, seat designs have become much more complex and demanding. New manufacturing technology has been developed to create bolder designs at lower costs. Advances in seat foam, suspension, trim attachment and trim materials have offered designers the flexibility and numerous choices to create the seats that these new interiors demand.
However, the complexity of these new designs has its price: the design development cycle is no longer short or simple. Refining a seat's design means more prototypes need to be built--often dozens. The time required to build such a large number of prototypes and the accompanying seat design approval process stretches to months of reviewing and revising the seat's final appearance.
Hence, there is a need to not only reduce design development time but also allow design flexibility.
Various methods and systems are available for collecting three-dimensional data for digitization of a three-dimensional object. This data can be obtained from non-contact devices such as camera-based systems or fine contact devices such as portable coordinate measuring machines such as disclosed in the Raab U.S. Pat. Nos. 5,402,582; 5,412,880; and 5,510,977. U.S. Pat. No. 5,255,352 discloses various contact and non-contact devices. However, in general, input data for such systems may be obtained from a CAD system; by scanning a physical part, such as by laser scanning; portable coordinate measuring machines; Moray interferometry; data acquisition systems, and the like.
U.S. Pat. No. 5,107,444 discloses a method for converting a three-dimensional image into a two-dimensional flat pattern that is a true representation of the three-dimensional surface of an object. The invention provides a numerical solution that provides minimum deviation from the true solution to the flattening problem in regions of substantial amounts of Gaussian curvature. This is accomplished in a computer-assisted design system by generating a three-dimensional mesh conforming to the topology of the three-dimensional surface and includes lines intersecting at nodal points to define polygonal elements between the nodal points. The polygonal elements are mapped to a location in a two-dimensional flat plane where the polygonal elements share at least one side with other polygonal elements previously mapped to the flat plane. The length of the shared side is distorted to conform to the length of the shared side of the other polygonal element. The distance between corresponding nodal points in the flat plane and on the three-dimensional surface are compared in order to determine the amount of distortion and are adjusted in response to the results of the comparison. This global adjustment is recursively carried out every time a complete row of elements is added to the developing pattern and when the pattern is complete. The patent further describes tools by which the user may apply his or her creativity and experience to make modifications to the pattern piece. The modifications, or cuts, are mapped back to the three-dimensional surface, which is then reflattened in order to determine the effect of the user-initiated modifications.
As addressed in U.S. Pat. No. 5,448,687, it is conventional to model the surface of complex objects, such as automobile seats, by tiling many surfaces together to define the form of the object. For example, an automotive seat bottom, seat back or seat head rest is each typically defined by up to 10 or more different mathematical surfaces. Each surface combined in this manner has its own parameter space and mathematical surfaces do not necessarily define the particular surface region of a three-dimensional object for the purposes of unwrapping and flattening the three-dimensional object into a two-dimensional pattern shape. Where one or more of the surfaces that are tiled together to form the surface region of the three-dimensional object includes multiple non-developable (i.e., having substantial amounts of Gaussian curvature) adjacent surfaces, the ability to find an optimum solution is further complicated.
U.S. Pat. No. 5,448,687 seeks to find the optimum solution noted immediately above by growing a regional mesh on the three-dimensional surface region conforming to the topology of the surface region independent of the surface boundaries. In this manner, the mesh coincides with and spans the mathematical definition of the corresponding surfaces.
U.S. Pat. No. 5,255,352 discloses an algorithm for mapping a surface detail (i.e., bit map) image to a two-dimensional flattened pattern piece representation of the surface and thereafter mapping this representation to a three-dimensional surface. The invention maps color/texture pixels to create a 3-D image on a screen of the system including appropriate curvature and shading.
Other U.S. patents relating to such data manipulation include U.S. Pat. Nos. 4,888,713; 5,016,183; 5,175,806; 5,218,671; and 5,222,206.
The patents to Abrams et al. (U.S. Pat. No. 5,587,913), Ebenstein et al. (U.S. Pat. No. 5,414,647), Pomerantz et al. (U.S. Pat. No. 4,961,154), and Carver et al. (U.S. Pat. No. 4,937,768) generate three-dimensional articles (or images) based on data provided by a CAD system. The patent to Fink et al. (U.S. Pat. No. 5,370,692) is an example of the numerous references dedicated to the production of prosthetic devices using CAD-like systems.
The patent to Cavendish et al. (U.S. Pat. No. 5,119,309) describes a feature-based method of designing automotive inner panels. This system accepts as input a feature based information set and produces a composite of the surface with a user-specified degree of smoothness.